Eg-TEC I+II

1 Terminology / Symbols1.3 Nitrox information (O 2 information)For dives with compressed air in normal recreational diving, nitrogen is the decisive gas for the decompressioncalculations. When diving with Nitrox, the risk of oxygen toxicity rises with the increase of the fractionof oxygen and the increase of depth and can limit dive time and the maximum depth. TEC includesthis in the calculations and displays the necessary information: Fraction of oxygen: The fraction of oxygen in the Nitrox mixture can be set between21% (normal compressed air) and 100% in 1% increments. Yourselected mix will be the basis for all calculations.ppO 2 max.Maximum allowed partial pressure of oxygen: the higher the fraction of oxygenin the mixture, the shallower the dive depth at which this value of thepartial pressure of oxygen is reached. The depth at which ppO 2 max. is reachedis called Maximum Operating Depth (MOD). Default setting is 1.4 bar, but it canbe set by means of SmartTRAK between 1.0 and 1.95 bar. When you enter thesettings for the gas mixture, TEC will display the ppO 2 max. limit setting and thecorresponding MOD. TEC warns the diver audibly and visually once the depthis reached at which the ppO 2 reaches the maximum allowed value.• The partial pressure limit set by means of SmartTRAK can be reduced manuallyat TEC (->18, setting the gas mixture).• The CNS O 2 % value/alarm is not influenced by the selected ppO 2 max. setting.Oxygen toxicity: With the increasedpercentage of oxygen, the oxygen inthe tissues (especially in the centralnervous system (CNS)) becomes important.If the partial pressure of oxygenrises above 0.5 bar, the CNS O 2value increases, if the partial pressureof oxygen is below 0.5 bar, theCNS O 2 value decreases. The closerthe CNS O 2 value is to 100%, thecloser the limit where symptoms canoccur. See page 21.CNS O 2 %decreasesCNS O 2 %increasesppO 20,21 bar0,5 barWARNINGNitrox diving may only be attempted by experienced divers after proper trainingfrom an internationally recognized agency.16III UWATEC ® Smart dive computers